General Medical Information

Adrenal Glucocorticoids

David M. Barrs

Adrenal insufficiency in otolaryngology patients is usually due to prior long-term steroid use with suppression of the hypothalamic-pituitary-adrenal axis. The normal oral daily maintenance dose of hydrocortisone is 20 mg in the morning and 10 mg in the afternoon. Prednisone is 4, methylprednisolone is 5, and dexamethasone is 25 times more powerful than hydrocortisone. Patients who have been on more than 5 mg of prednisone each day for 3 weeks in the preceding year are assumed to have suppressed endogenous production of cortisol and should be treated with supplemental steroids for surgery. Patients who are currently on steroids, those with known adrenal insufficiencies, and even patients with Cushing syndrome also should be covered with supplemental steroids in the perioperative period. Large quantities of cortisol, in the range of 300 mg daily, are released from the adrenal gland during stresses such as surgery. The dose of administered steroids is designed to be in this same range (Table 18.5). Failure to provide replacement glucocorticoids can result in loss of vascular tone with hypotension that is refractory to fluids or pressor agents.

Primary adrenal insufficiency is rare and may present perioperatively as acute adrenal crisis. The symptoms are not specific and can include hypotension, weakness, dizziness, fever, nausea, vomiting, and abdominal pain. In the face of unexplained hypotension, adrenal insufficiency must be considered and treated empirically if hypotension is refractory. Blood should be drawn for measurement of serum levels of cortisol, electrolytes, glucose, blood urea nitrogen, and creatinine. An immediate bolus of 200 mg of hydrocortisone is given intravenously, followed by fluids containing glucose and saline to correct volume deficiencies.